It doesn't seem right, though. I mean, even if he didn't need him right then and there, why wouldn't he take him out of the equation anyway? He's pretty much a variable -- he can go wherever and whenever he wants. It seems odd that even if he knew who Hiro was that he wouldn't make a go for him just to get him out of the way. And he had a chance -- Hiro was still in the bathroom when everybody else was finding the waitress' body. He could have killed him then.